In recent years, Internet of Things (IoT) solutions that collect pieces of data from a large number of devices such as sensors and apparatuses collecting predetermined information and utilize them for service have spread. Examples of the IoT solutions include solutions for improving productivity and quality in factories and solutions for efficiently using energy.
Bluetooth (registered trademark) low energy (BLE) devices have recently increased as devices that are used in IoT. The BLE is a short-range radio communication standard and a configuration in which pieces of notification information as pieces of data transmitted from the BLE devices are connected to a center server through a gate way (GW) device arranged in the range where radio waves reach is used in many cases. There are two methods for acquiring the pieces of data from the BLE devices by the GW device. Both of the methods use scanning processing with which the GW device detects the BLE devices and advertise messages with which the BLE devices notify of their own presences.
With the one data acquisition method, when the GW device receives the advertise message output from the BLE device during execution of the scanning, the GW device transmits and receives data to and from the BLE device as an output source of the advertise message and acquires notification information. Hereinafter, the BLE device that transmits the notification information using this data acquisition method is referred to as a “beacon-type” BLE device. The beacon-type BLE device includes a type of device that incorporates the notification information into the advertise message and transmits it to the GW device.
With the other data acquisition method, when the GW device receives the advertise message output from the BLE device during execution of the scanning, the GW device performs connection processing with the BLE device as an output source of the advertise message. Then, the GW device transmits and receives data to and from the BLE device with which the connection processing has been completed to establish connection and acquires the notification information. When the GW device acquires the notification information from the BLE device with which connection has already been established, it acquires the notification information without performing the scanning, the reception of the advertise message, and the connection processing. Hereinafter, the BLE device that transmits the notification information using this data acquisition method is referred to as a “connection-type” BLE device.
When the GW device performs the scanning and data transmission and reception during execution of the connection processing with the connection-type BLE device, the connection processing is finished and connection with the BLE device is not established. For this reason, the GW device detects no BLE device through the scanning and acquires no notification information from other BLE devices during the connection processing. In the case in which there are the BLE devices subordinate to one GW device, the GW device does not acquire the pieces of notification information that are transmitted from the other BLE devices during the connection processing when performing the connection processing with the connection-type BLE device. Missing of the notification information therefore occurs and service quality of service involving provision of the pieces of notification information of the BLE devices is deteriorated.
Several methods can be considered in order to avoid the deterioration in the service. For example, a method in which the GW device has a plurality of interfaces can be considered. This method enables the GW device to perform the connection processing and the detection of the BLE devices by the scanning and acquisition of the pieces of notification information from the other BLE devices in parallel. In addition, there is, for example, a method in which reception intervals of the pieces of notification information from the other BLE devices are monitored and the connection processing is executed in a time band during which data transmission and reception are not performed.
Furthermore, there is a conventional communication control technique in which connection with a plurality of terminals is performed while lowering the priority of connection with a terminal under a bad radio wave environment. There is also a conventional technique in which data transfer capable of being delayed is delayed in congestion. Moreover, a conventional technique in which assignment of channel time is changed depending on types of services that pieces of transmission and reception data provide has been known. A conventional technique in which connection with apparatuses making short-range wireless communication is performed in the order of priority by adding the priorities to the apparatuses has been also known.
Conventional techniques are described, for example, in Japanese Laid-open Patent Publication No. 2013-211815, Japanese National Publication of International Patent Application No. 2006-520550, Japanese Laid-open Patent Publication No. 2005-198305, and Japanese Laid-open Patent Publication No. 2006-319946 are examples of the conventional techniques.
With the method in which the interfaces are mounted in the GW device, it is difficult to add a communication interface because cost for introduction and operation is increased although addition of the communication interface is considered to be requested after operation. That is to say, it is difficult to prevent addition of the connection-type BLE device from influencing acquisition of the pieces of notification information of the other BLE devices and there is the risk that service quality is reduced. Furthermore, the method in which the connection processing is executed in the time band during which the data transmission and reception are not performed by the other devices has the risk that spare time becomes short and the connection is not completed when many BLE devices are present. In addition, when it takes a long time for the connection using spare time due to a worse radio wave status, acquisition failure of the notification information of another BLE device occurs.
Even with the conventional technique in which the connection with the terminals is performed while lowering the priority of connection with the terminal under the bad radio wave environment, it is difficult to reduce influences by the connection of the connection-type BLE device on information acquisition of the other BLE devices and there is the risk that the service quality is reduced. The same holds true for the usage of the conventional technique in which the data transfer capable of being delayed is delayed in congestion, the conventional technique in which the assignment of the channel time is changed depending on the types of services, and the conventional technique in which the connection is performed in the order of priority.